The STEM Lecture: Stratospheric Ozone: A Success Story by resident José M. Rodriguez will be given at 10:30 am in the Performance Hall and streaming. The Earth’s ozone layer in the stratosphere (about 7 miles up) provides crucial protection for life by absorbing damaging UV radiation from the Sun. This layer is naturally occurring, and in principle stable. But emissions of compounds engineered in the 1920’s can result in permanent destruction of ozone. Hear how this problem grew, the surprise of the Antarctic Ozone Hole, and how UN agreements have led us to see recovery of ozone. They remain encouraging examples of how international collaboration can address potential global catastrophes.